Your smartphone, tablet and other devices emit large quantities of blue light wavelengths. This tells your body "wake up!" when you should be getting ready to sleep. (2:50 min.)

It’s in our tap water, toothpaste and even in tea. Fluoride has helped reduce cavities in children for decades. Still, more than 70 years after Grand Rapids, Michigan, became the first city to fluoridate its drinking water, the practice remains controversial. Some worry that fluoridated drinking water can lead to health issues, but what is the scientific consensus? (3:14 min.)